In dicot stems, the hypodermis tissue is primarily collenchyma. Collenchyma provides mechanical support and flexibility to growing stems. In monocot stems, the hypodermis tissue is usually sclerenchyma, which consists of cells with thickened walls that provide strength and rigidity to the plant.
Thus, the hypodermis tissues in dicot and monocot stems are:
Collenchyma in dicots.
Sclerenchyma in monocots.
Therefore, the correct answer is: Collenchyma and Sclerenchyma.